United States-Mexico Land Ports of Entry Emissions and Border Wait-Time White Paper and Analysis Template

1.0 Executive Summary

1.1 Purpose

Delay and congestion at the ports of entry (POE) along the length of the United States (U.S.)-Mexico border present complicated problems for the commercial and private traffic using the facilities, and impact the surrounding communities and those employed at the border itself. There is a strong desire to implement strategies that reduce emissions at the border to both reduce potential exposure to unhealthy levels of exhaust pollutants and to help regions attain the national ambient air quality standards.

This project developed an analysis template for emissions associated with the ports of entry, and demonstrates its use through two case studies. Results from the case studies identify candidate best practices and performance measures for use as an input during the initial phases of development for projects that alter the border infrastructure or the operational characteristics of the ports of entry.

Projects, solutions, and strategies that can be directly evaluated by the emissions analysis protocol fall into three categories:

Staffing and Management – Solutions that address the institutional, policy, or regulatory environment that governs the management of the region's cross-border network, including Customs and Border Protection (CBP) staffing levels and bridge hours of operation;

Technology – Solutions that leverage existing technology or implement new technology applications to improve the efficiency of cross-border movements, inspections, or information available to passengers, carriers, or shippers; and

Traffic Engineering and Infrastructure – Solutions that relate to the condition or physical capacity of the port of entry infrastructure or approach network, as well as operational solutions that relate to how the system is being utilized.

Additionally, other types of strategies such as pricing, and policies that effect travel behavior can be evaluated to the extent that changes in delay can be estimated through traffic operations analysis.

1.2 Approach

The framework for the approach is shown as the flowchart provided in Figure 1.1. The process involves developing representative emission rates and then combining those rates with the corresponding vehicle activity. Differences between scenarios can be quantified.

Stop-and-go queuing reflecting dense congested traffic in storage lanes similar to that found in the storage lanes providing immediate service to the primary inspection booths. These types of queues were found to have average speeds of less than one mile per hour.

Creeping queues characterizing vehicle behavior on congested roadway segments that feed the stop-and-go queue lanes. The queues have more of a creeping behavior than a stop-and-go behavior because each lane feeds multiple stop-and-go queue lanes. Speeds on links that have creeping queues average about five miles per hour.

Uncongested operation is used to describe the travel on roadway segments leading up to queue links; average speeds for these links are in the 25 to 35 miles-per-hour range.

The vehicle idle and start emissions resulting from the secondary inspections process and the commercial cargo inspection process also are captured by the analysis template.

Figure 1.1 Analysis Template Approach

Source: Cambridge Systematics, Inc.

Note: The analysis protocol considers three types of vehicle movements that capture the range of emissions as vehicles approach the border crossing. The needed vehicle activity data and corresponding emissions are readily quantifiable for screening analysis or can be applied in a detailed manner for more sophisticated applications.

1.3 Case Study

The Ysleta-Zaragoza port near El Paso was used as a case study to demonstrate the approach. The case study focused on 2010 and demonstrates PM2.5 and NOx emission calculations for four scenarios:

A "no delay" scenario representing a hypothetical best case where vehicles pass through the POE as if it did not exist. There are no inspections, no congestion, and no delays.

A "Privately Owned Vehicle (POV) Strategy" that shifts vehicles from the general purpose lanes to the faster SENTRI lanes.

A "commercial vehicle strategy" that assumes U.S. and Mexican cargo inspections are combined to eliminate the queuing and delay associated with duplicative inspections.

Results of the case studies are shown in Figure 1.2 and Figure 1.3. Even though the commercial traffic (generally consisting of heavy trucks) is much lower than private vehicle traffic (generally consisting of passenger vehicles), the commercial vehicles account for most of the PM2.5 and NOx emissions.

Figure 1.2 2010 Ysleta-Zaragoza Northbound Daily PM2.5 Emissions

Source: Cambridge Systematics, Inc.

Figure 1.3 2010 Ysleta-Zaragoza Northbound Daily NOx Emissions

Source: Cambridge Systematics, Inc.

1.4 Findings

Recommended best management practices focus on minimizing queue delay and congestion at the border.

Minimize the number of booths and combine inspections. Each point where a vehicle needs to stop for a specific check has stop-and-go queuing leading up to the booth and idling at the booth itself. Emissions from each of these processes may be as much as five percent of the controllable emissions at the port of entry.

Minimize queue vehicle miles of travel (VMT) and/or minimize delay. For queued vehicles, gram-per-mile emission rates are generally on the order of two times the emission rate for uncongested VMT. Minimizing delay is analogous to minimizing queue VMT; but time spent parked should not be included in the tabulation of delay.

Park rather than stack vehicles. Some new border crossing designs include a storage parking lot where vehicles can be parked rather than idle/creep while waiting for cargo inspections. For commercial vehicles, the amount of creeping VMT inside of the cargo inspection areas may be similar to the queue lengths approaching the border.

Examples of strategies that would be compatible with these best management practices would be: consolidating toll and inspection booths; appointment systems; and preclearance of more vehicles and vehicle occupants through programs such as SENTRI, FAST, and the use of Ready Lanes.

Candidate performance measures include:

Emissions in terms of grams per vehicle processed through the port of entry;

The total mass of pollutants emitted at the port of entry, or process within the port of entry;